sftp-server implements the server side of the SSH File Transfer Protocol as defined in the IETF draft-ietf-secsh-filexfer.
sftp-server is a subsystem for sshd(1M) and must not be run directly. Command-line flags to sftp-server should be specified in the Subsys-
tem declaration. See sshd_config(4) for more information.
To enable the sftp-server subsystem for sshd add the following to /etc/ssh/sshd_config:
Subsystem sftp /usr/lib/ssh/sftp-server
See sshd_config(4) for a description of the format and contents of that file.
There is no relationship between the protocol used by sftp-server and the FTP protocol (RFC 959) provided by in.ftpd.

OPTIONS

Valid options are listed below. As stated above, these are to be specified in the Subsystem declation of sshd_config.
-f log_facility
Specifies the facility code that is used when logging messages from sftp-server. The possible values are: DAEMON, USER, AUTH, LOCAL0,
LOCAL1, LOCAL2, LOCAL3, LOCAL4, LOCAL5, LOCAL6, LOCAL7. The default is AUTH.
-l log_level
Specifies which messages will be logged by sftp-server. The possible values are: QUIET, FATAL, ERROR, INFO, VERBOSE, DEBUG, DEBUG1,
DEBUG2, and DEBUG3. INFO and VERBOSE log transactions that sftp-server performs on behalf of the client. DEBUG and DEBUG1 are equiva-
lent. DEBUG2 and DEBUG3 each specify higher levels of debugging output. The default is ERROR.

EXIT STATUS

The following exit values are returned:
0 Successful completion.
>0 An error occurred.